Art of utilizing high-frequency electric oscillations.



D. W. BROWN.

ART OF UTILIZING HIGH FREQUENCY ELECTRIC OSCILLATIONS.

APPLICATION FILED was. 1916.

1,255,289. Patented Feb. 5,1918.

2 SHEETS-SHEET I.

IIII S-I-WdWIC I/ D. W. BROWN.

ART OF unuzme HIGH FREQUENCY ELECTRIC OSCILLATlONS.

APPLICATION FILED AUG-9, 1916.

Patented Feb. 5, 1918.

2 SHEETS-SHEET 2.

jhq vem/ba w UNITED STATES PATENT OFFICE.

DAVID W. BROWN, OF NEW YORK, N. Y.

ART OF UTILIZING HIGH-FREQUENCY ELECTRIC .OSCILLATIONS.

Application filed August 9, 1916.

To all whom it may concern:

Be it known that 1, DAVID W. BROWN, a citizen of the United States, and a resident of the borough of Manhattan, city of New York, in the county and State of New York, have invented certain new and useful Improve- ;ments in the Art of Utilizing High-Frequency Electric Oscillations, of which the following is a specification.

This invention relates to improvements in the art of utilizing high frequency electric oscillations.

In my application for patent heretofore filed in the United States Patent Office on October 1st, 1914:, Serial Number 86%,393, I have broadly described and claimed both the method and various apparatus for increasing the effect of high frequency electric oscillations upon detectors. In this present application, I set forth certain particular apparatus and methods for attaining that result, and that in the case when there is employed 'a spark gap detector in the aerial receiving While this application is restricted to that special type of apparatus and the method of operating the same, it can be best explained by reference to the principles involved in the general invention set forth in my said application, Serial No. 864,393, filed October 1st,

In wireless telegraphy, wireless telephony and other arts depending upon the oscillation of Hertzian waves transmitted from generators at a sending station to devices at tric oscillations as to permit local electric Specification of Letters Patent.

Patented Feb. 5, 1918.

Serial No. 113,859.

currents in circuit with them to affect various instruments in the desired manner, and to ultimately produce desired results at the receiving station; as, for example, to operate telegraph keys, telephones, cause explosions of explosive substances, start, stop and control machinery, and produce various electric and chemical results and numerous other results.

It has been found, however, that with any given generator at the sendingstation, there is a distance between the receiving station and the sending station beyond which ,the oscillations set up at the receiving station by Hertzian waves sent from the sending station will not properly affect detectors at said receiving station; and, therefore, beyond said distances, the desired results of telephony, wireless telegraphy, and other desired results can not be attained. It is therefore the purpose ofthis invention to so increase the effeats of said oscillations 011 detectors, that oscillations which, of themselves and Without this invention, would be too feeble to properly affect the detectors, will hawe their efficiency so increased that they will properly affect said detectors, and thus will enable the desired results of telephony, wireless telegraphy and other desired results to be attained at greater distances from the sending station than are now possible.

I effect the desired result by generating and durably maintaining a field of electric energy about a detector independently of said oscillations and their generators. For I have found that when oscillations come into such an independent field their effect upon the detector is greatly augmented, and

oscillations which, without such a field, would be too feeble to properly affect the detector, will, with said field, have their effect on the detector so increased that they will now properly affect it, and will thereby enable desired results of telephony, wireless 'telegraphy and other desired results to be attained. at distaneesfrom the sending station greater than would otherwise be practicable. Said field of electric energy. is generated independently of said oscillations and their generators, and the generator of. said independent field and all Wiring thereof being electrically insulated or disconnected from the detector and its wires and local circuits and instruments, has the important property, that it does not of itself and without said oscillations, improperly affect the detector, but it is only when said oscillations enter said field that said detector is affected.

In the present application, the aerial circuit at the receiving station, and preferably the aerial itself, is interrupted, or gapped, the interruption being hereinafter termed a spark-gap and the separated ends of the aerial at said gap being provided with spark balls or other more or less extended surfaces. Said spark gap is electrically connected with a source of current electricity, independent of the high frequency oscillations set up on the aerial by the Hertzian waves coming from the sending station, and preferably such a generator or source as delivers an alternating current of low period of alternation to the spark gap, and a permanent field of electric energy is thereby produced at said spark gap which field is wholly independent of such oscillations. The potential of said independent current at said gap is normally too low to spark or surge across said gap, but is nevertheless much higher than is suflicient to affect the detector. Therefore said spark gap terminals are electrically separated or as hereinafter termed, insulated, from the detector of the local circuit, so that said independent current of electricity cannot reach said detector and improperly operate it or the receiving or recording instruments of the 10- cal circuit. To prevent the leakage of said current to earth a condenser or other suitable device is interposed between said spark gap and earth. When high frequency oscillations set up by Hertzian waves enter said independent field of electric energy at said gap, said field, so to say, vivifies, or intensifies said oscillations so that oscillations which, without said independent field, would be too weak to affect said detector and produce the proper operation of the instrumentalities of the local circuit, will, when said independent field of electric energy is maintained at said gap, have their eflect on the detector so increased as to properly affect it and insure the proper operation of the instrumentalities of the local circuit.

By providing the interruption or gap in the aerial circuit, as hereinbefore stated, there is produced a maximum of potential of the high frequency oscillations, or waves, at said gap, and the gap becomes a so-called ,loop, or point of maximum wave effect,

and this condition is also highly favorable to the increasing of the effect of the oscillations on the detector, and the provision of the gap pendent field of electric energy thcreat are thereby rendered the more advantageous,

and the maintenance of the inde-- both for the increasing of the effect of the oscillations on the detector and for the resonance or tuning of the receiving circuit.

Thus this invention permits of the sending of signals or intelligence over greatly increased distances between the sending and the receiving stations, and the production of many other effects at distances from the sending stations which are so great that, without this invention, such effects could not be produced at the receiving station.

The said form of the invention herein set forth has great advantages in the ease with which it can be constructed and applied, in the ready control of the intensity of the electrification of the space between the spark balls, thereby facilitating the so-called tuning of the receiving circuit, and in the readiness with which it can be combined with the intensifiers of the high frequency electric oscillators, modifications of which combinations are illustrated in several figures of the drawings which accompany this specification. In this invention also, the permanent field of electric energy is generated by dynamic, or current electricity, since the spark gap is connected with a generator supplying current electricity, or electricity in a dynamic form, and which is indicated by my tests to be much more efficient in vivifying the high frequency oscillations than is the magnetic (or as I term it static field) around the poles of permanent magnets; and especially advantageous is an alternating current, which seems particularly to possess the property of vivifying the weak oscillations which enter the permanent field.

Referring to the drawings which accompanying the specification to aid the description, and which illustrate modifications of the invention in diagrammatic manner, the detector in the local circuit is indicated as a coherer, but of course it may be of any type of detector; and it will be also understood that the resonance or tuning of the apparatus at the sending and the receiving station may be eifected in any usual manner, and that under suitable circumstances, and especially for short distances, untuned systems may be used. In the said drawings Figure 1 is an elevation, partly in section, of receiving apparatus wherein the spark gap is employed in combination with one arrangement of oscillation intensifiers, the detector being in circuit with said intensifier tubes; Fig. 2-illustrates another combination of the spark gap and the oscillation intensifiers, wherein the detector is in circuit with the wires of said intensifiers; Fig. 3 illustrates a direct coupled arrangement of the spark gap and detector without the oscillation intensifier tubes; Fig. 4 illustrates an inductively coupled receiving system, without the oscillation intensifiers; Fig. 5 illustrates an inductively coupled receiving systhough this is not indispensable, is provided tion intensifiers, the detector being in circuit with the wires of the oscillation intensifiers; Fig. 7 is a cross-section of an oscillation intensifier on larger scale.

Fig. 8 is a broken diagrammatical representation of parts of a receiving system having a generator of low frequency alternating currents for producing the independent field of electric energy at the spark-gap.

Referring particularly to Fig. 1, the receiving aerial A A, preferably earthed alwith a spark gap and balls 8 s, which may be adjustable. The spark gap balls or wires thereof are connected by wires e 03 with an independent source of electricity G, which may be any suitable source of electricity, as a battery for developing constant current, as shown in Fig. l or a generator of low frequency alternating currents as diagrammatically indicated in Fig. 8. A constant current generator may be used but an alternating current appears to have a greater effect A on the high frequency oscillations than does a constant current of equal potential. The current supplied to the spark gap is of such strength as will not normally spark or surge across the gap, and the leakage of the current to earth is prevented by the condenser C (which may be an adjustable condenser) interposed in the aerial between said spark gap and the earth for, as will be seen, the condenser C and. earth connection A of the aerial, are, so to say, short circuited by the wires ed of the circuit from the generator G, (Fig. 8) which wires form the direct path for the alternating. current. There is therefore no leakage of current to earth, even should there be a weak induced alternating current to and fro between the lower condenser plate and earth, and a'variable resistance R is preferably provided in the independent generator circuit.

Branch wires a and b, are connected with I said aerial, and preferably on either side of said spark gap 8 s. In the modification illustrated in Fig. 1 the free ends of said wires a b are stopped with balls w y, or with blunted ends.

to allow the air to circulate freely. The said oscillation intensifiers are fully set forth and described in my application Serial Number 865,619, filed in the United States Patent Office October 8, 1914, and further description of them is not here necessary.

The local circuit is indicated by the wires h i, and will be provided with any suitable relay, recording and registering apparatus.

The operation is as follows: As hereinbefore stated dynamic or current electricity is continuously supplied to the spark gap balls 8 s, but of a potential sufficiently low not to normally spark or surge across said gap. Consequently a field of electric energy is permanently maintained at said gap, which is wholly independent of any high frequency oscillations received on the aerial A A. The escape of this electricity to earth is prevented by the condenser C, and the said current cannot reach or afiect the detector D and the said local circuit instrumentalities, because said dectector D is in circuit with the intensifier tubes, which are insulated from the wires a, 6. Therefore a current ofconsiderable strength may be supplied to said spark gap balls 8 s, and a field of corresponding strength may be maintained at said spark gap without afiecting the coherer D or the instruments of the local circuit.

The separation of the relatively strong current of electricity which is supplied to the spark gap balls, from the detector and the other local circuit instrumentalities is of great importance and practically indispensable, since without such separation the detector would be improperly and constantly operated. Whereas, when the said strong current is thus separated from the detector and the local circuit instrumentalities, it is only when the high frequency oscillations are set up in the aerial by the Hertzian waves, that said detector and local circuit instrumentalities are set in action.

When high frequency oscillations are set up by Hertzian waves arriving on the aerial A A from the distant sending station, the said constant field of electric energy at said spark gapgreatly, so to say, vivifies said oscillations, the oscillation intensifier tubes K K become intensely excited, and the efi'ect of the said high frequency oscillations on the detector D is greatly increased over what their efl'ect'would have been had not the con stant field ofelectric energy been maintained at saidgap; and consequently the instrumentalities in the local circuit will be operated even when high frequency oscillations are received on said aerial which would be too weak to operate them without such permanent field of electric energy.

The arrangement of the apparatus in Fig. 2 is practically the same as in Fig. 1, er:- cepting that the detector D in Fig. 2 is 1n circuit with the wires w a, b b, condensers M N (which may be adjustable) being now located respectively between said detector D, and said wires a and b to prevent the current from said independent generator G from affecting said detector D and the instrumentalities of the local circuit. condensers M and N are not necessary in the arrangement of Fig. 1, but could, of course, be used if desired. The operation of the apparatus of Fig. 2 will be evident from the description of the operation of the apparatus of Fig. 1 without further explanation.

In the apparatus of said Figs. 1 and 2, oscillation intensifier tubes are employed, but they are not indispensable with said spark gap and permanent fields of electric energy; and therefore I illustrate in Fig. 3 close connected receiving apparatus without such oscillation intensifiers. In this modification the detector D is connected with the branch wires 0: a, b b, condensers M N being interposed between the said aerial and the said detector to prevent the independent current from the generator G from improperly affectlng the said detector D and instruments of the local circuit. The operation of this form of apparatus will be clearly understood from explanations and descriptions hereinbefore contained.

Figs. 1, 2 and 3 illustrate modifications of close coupled receiving circuits with said spark gap and independent field of electric energy; Figs. 4, 5 and 6 illustrate inductively coupled circuits having said spark gap and independent field of electric energy. In sald Fig. the aerial A is indirectly connected with the detector D through a transformer T T in the manner now commonly practised; said transformer being preferably adjustable to vary inductance and aid in producing resonance. The

branch wires 0, a, Z) Z), are in series with the coil T of said transformer and with the detector D, and condensers M N are interposedbetween said detector and transformer. The construction and arrangement of other parts of this modification 0f the ap paratus will be understood from the explanations and descriptions hereinbefore contamed. The operation of this modification wlll also be clear from explanations herelnbefore contained, it only being added that the surge set up on the aerial A, as has been before set forth, when Hertzian waves arrlve from the distant sending station, now acts lnductively on said detector D through 1ts effect on the secondary T of said transformer.

In Fig. the inductive connection of the detector WltlL the aerial, spark gap and independent field of electric energy is comb1ned w1th my high frequency oscillation ntensifier tubes K K, and the detector D is now in series with said tubes'K K, and

Said

the condensers M N may be omitted or may be used; Fig. 5 showing the apparatus without the condensers M N. The operation of this modification of the apparatus will be plain from explanations and descriptions hereinbefore contained.

The apparatus illustrated in Fig. 6 is substantially the same as that illustrated in Fig. 5, except that the detector D is now in series with said wires a a, b b, and condensers M N are now interposed between said detector D and the transformer coil T. The operation of this modification will be clear from explanations and descriptions hereinbefore contained.

Now having described my improvements I claim as my invention.

1. The method of increasin the effect of high frequency electric oscil ations on detectors, consisting in generating and maintaining an independent field of electric energy on an interrupted receiving aerial by electric current of potential high enough to affect said detector, and insulating said current from said detector.

2. The method of increasing the effect of high frequency oscillations on detectors, consisting in generating and maintaining a field of electric energy on an interrupted receiving aerial independent of the high frequency oscillations by current electricity of strength more than sufficient to affect the detector, and insulating said independent current from the detector and earth.

3. The combination in apparatus for the purpose described, of an interrupted aerial circuit, a detector operatively connected with said aerial circuit, a source of electricity operatively connected with said aerial and adapted to continuously charge said aerial at the interruption and maintaln a field of electric energy at the interruption independent of high frequency oscillations on said aerial and of a potential higher than suflicient to affect said detector, and means for insulating said charge from said detector.

4. The combination in apparatus of the kind described, of a receiving aerial provided with a gap, a detector operatively congap and adapted to maintain a field of electricity at said ap independent of the high frequency oscil ations on said aerial, and means to insulate said current from said detector.

6. The combination with a receiving aerial provided with a gap and a source of electricity to maintain an independent field of electric energy at said gap, of oscillation intensifiers comprising branch wires operatively connected with said aerial and electrically conductive envelops about said branch wires but insulated therefrom, and a detector operatively connected with said oscillation intensifiers.

Signed at New York city, in the county of New York, and State of New York, this 8th day Of August, A. D. 1916.

DAVID W. BROWVN.

Witnesses:

WILLIAM PATTERSON, WALTER N. HARRIS. 

